CONCORD, North Carolina (CNN) – John McCain stepped up his rhetoric against Barack Obama on taxes in his weekly radio address, comparing his plan to 'socialist' programs that would “convert the IRS into a giant welfare agency, redistributing massive amounts of wealth.”

The remarks were part of a theme McCain has used since the final presidential debate that criticizes Obama’s philosophy, but his most recent comments were the first time he directly invoked the word 'socialist.'

In the radio address that aired Saturday morning, McCain didn't directly call Obama a socialist, but he let the now-famous Joe 'the Plumber' Wurzelbacher nearly do it for him.

“You see, [Obama] believes in redistributing wealth, not in policies that help us all make more of it. Joe in his plainspoken way, said this sounded a lot like socialism,” McCain said.

In an interview with ABC last week, Wurzelbacher said Obama's proposal to raise taxes by 3 percent on those making $250,000 and over is a "very socialist view."

Republican VP candidate Sarah Palin has used the word in speeches the last two days as well.

Also in the pre-taped radio address, McCain said, “At least in Europe, the socialist leaders who so admire my opponent are upfront about their objectives. They use real numbers and honest language. And we should demand equal candor from Senator Obama. Raising taxes on some in order to give checks to others is not a tax cut it's just another government giveaway.”

McCain did not repeat the wording in his appearance at a rally in Concord, but did allude to those European socialist countries that like to "spread the wealth around."

"Spread the wealth around. We have seen that movie before in other countries and attempts by the liberal left before," McCain said.

In his speech, McCain also said said, “This explains some big problems with my opponent's claim that he will cut income taxes for 95 percent of Americans. You might ask: How do you cut income taxes for [95] percent of Americans, when more than 40 percent pay no income taxes right now? How do you reduce the number zero? That's the key to Barack Obama's whole plan: Since you can't reduce taxes on those who pay zero, the government will write them all checks called a tax credit. And the Treasury will have to cover those checks by taxing other people…the Obama tax increase would come at the worst possible time for America.”

Asked why McCain used the word socialist in the radio remarks, a spokesman told CNN, “That’s what it is, 'spreading the wealth' around is socialism.”

In a July interview with the Kansas City Star, McCain said Obama had the “most extreme” record in the Senate. He said at the time in a comment he has since repeated on the trail, “his voting record… is more to the left than the announced socialist in the United States Senate, Bernie Sanders of Vermont."

Pressed if he considered Obama a socialist, McCain shrugged and said, “I don't know."

In remarks this week, Palin has referred to Obama’s encounter with Wurzelbacher in Ohio last Sunday. At a rally in West Chester, Ohio Friday where one banner in the crowd read, “Obama is a Socialist/Marxist," Palin said, “Joe suggested that that sounded a little bit like socialism,” she said. “Whatever you call it, I call it bad medicine for an ailing economy, and it’s what Barack Obama will do to those who want to create jobs and we’re willing to call Barack Obama on it.”

In North Carolina Saturday, McCain also invoked the specter of a huge filibuster proof Democratic majority in the house.

“By the way did you happen to see that Speaker Pelosi said she anticipates a 250 seat majority, “said McCain to loud boos from the crowd. “My friends we can’t let that happen. They’ll raise taxes and increase spending and they will concede defeat in Iraq.”